Radio communication method and a base station and user terminal thereof

Abstract

A wireless communication method for transmitting data signals of first and second users using first and second subcarrier groups, respectively, and transmitting pilot signals of the first and second users by multiplexing the pilot signals to the data signals, including allocating the pilot signals of the first and second users to different frequencies, where each of the pilot signals is generated based on Zadoff-Chu sequence; and mapping subcarrier components of the pilot signals so that one or more subcarrier components of higher frequencies and one or more subcarrier components of lower frequencies in the transmission band become identical, in regard to the pilot signals of each of the first and second users.

What is claimed is: 
     
       1. A wireless communication method for transmitting data signals of a first user and a second user using a first subcarrier group and a second subcarrier group, respectively, and transmitting a pilot signal of the first user and a pilot signal of the second user, the method comprising:
 allocating the pilot signal of the first user and the pilot signal of the second user to different frequencies, wherein each pilot signal is generated based on a Zadoff-Chu sequence; and 
 copying one or more subcarrier components of lower frequencies in the pilot signal of the first user to one or more subcarrier components of higher frequencies in the pilot signal of the first user and copying one or more subcarrier components of lower frequencies in the pilot signal of the second user to one or more subcarrier components of higher frequencies in the pilot signal of the second user. 
 
     
     
       2. A wireless communication system for transmitting data signals of a first user and a second user using a first subcarrier group and a second subcarrier group, respectively, and transmitting a pilot signal of the first user and a pilot signal of the second user, the system comprising:
 an allocating circuit configured to allocate the pilot signal of the first user and the pilot signal of the second user to different frequencies, wherein each pilot signal is generated based on a Zadoff-Chu sequence; and 
 a circuit configured to copy one or more subcarrier components of lower frequencies in the pilot signal of the first user to one or more mapped subcarrier components of higher frequencies in the pilot signal of the first user and to copy one or more subcarrier components of lower frequencies in the pilot signal of the second user to one or more subcarrier components of higher frequencies in the pilot signal of the second user. 
 
     
     
       3. A first wireless communication terminal in a wireless communication system including the first wireless communication terminal and a second wireless communication terminal which use a first subcarrier group to transmit a first pilot signal and a second subcarrier group to transmit a second pilot signal, respectively, the first wireless communication terminal comprising:
 a multiplexer circuit configured to multiplex subcarrier components of pilot signals generated based on a Zadoff-Chu sequence so that one or more subcarrier components of lower frequencies in the first pilot signal is copied to one or more subcarrier components of higher frequencies, the first pilot signal using frequencies different from frequencies used for the second pilot signal; and 
 a transmit circuit configured to transmit the multiplexed pilot signals to a base station. 
 
     
     
       4. A first wireless communication terminal in a wireless communication system including the first wireless communication terminal and a second wireless communication terminal which use a first subcarrier group to transmit a first pilot signal and a second subcarrier group to transmit a second pilot signal, respectively, the first wireless communication terminal comprising:
 at least one processor coupled with a memory, the at least one processor configured to cause the wireless communication terminal to: 
 multiplex subcarrier components of pilot signals generated based on a Zadoff-Chu sequence so that one or more subcarrier components of lower frequencies in the first pilot signal is copied to one or more subcarrier components of higher frequencies, the first pilot signal using frequencies different from frequencies used for the second pilot signal; and 
 transmit the multiplexed pilot signals to a base station.